Many people use mobile stations, such as cell phones and personal digital assistants (PDAs), to communicate with cellular wireless networks. Service providers that operate these networks typically distribute mobile stations to their subscribers, perhaps by selling the mobile stations at retail outlets or over the Internet, or perhaps by offering mobile stations at no cost to people that subscribe to a particular service plan, etc. Service providers then typically assign to each mobile station a telephone directory number—often known as a mobile identification number (MIN) or mobile directory number (MDN)—under which that mobile station may operate. Via a (e.g., manual or over-the-air) provisioning process, the service provider may cause the mobile station to store its MIN in what is known as its Number Assignment Module (NAM). Furthermore, a mobile station typically is provided at the time of manufacture with an electronic serial number (ESN), which identifies the mobile station as a unique physical device.
These mobile stations and networks typically communicate with each other over a radio frequency (RF) air interface according to a wireless protocol such as Code Division Multiple Access (CDMA), perhaps in conformance with one or more industry specifications such as IS-95 and IS-2000. Wireless networks that operate according to these specifications are often referred to as “1xRTT networks” (or “1x networks” for short), which stands for “Single Carrier Radio Transmission Technology.” Another protocol that may be used is known as Evolution Data Optimized (EV-DO), perhaps in conformance with one or more industry specifications such as IS-856, Release 0 and IS-856, Revision A. Of course, other protocols may be used instead or in addition, such as Global System for Mobile Communications (GSM), Time Division Multiple Access (TDMA), WiMax, and/or any others.
Such wireless networks typically provide services such as voice, Short Message Service (SMS), and packet-data communication, among others. A message-recording service may also be provided so that messages can be left for called parties. Message-recording services may facilitate the recording of voicemail messages and/or audio-visual messages via a calling party's mobile station, and the storage of the recorded messages in the service provider's wireless network for eventual access by called parties. Message-recording services may be used by a calling party when a called party is determined by a network to have not accepted a given call, which may occur for any number of reasons, including being away from a called device, not having the device turned on, being on another call, etc.